Improvement in file-cutting machines



Nrrn @raras ArtNr IMPROVEMENT IN FILE-CUTTING MACHINES.

Speciiication forming part of Letters Patent No. 42,!! E7, dated April5, 1864.

.To @ZZ whom, it may concern:

Be it known that I, WILLIAM T. NICHOL- soN, of the city and county ofProvidence, in the State of Rhode Island, have invented certain new anduseful Improvements in File- Cutting Machines; and I do hereby declarethat the following specification, taken in connection with the drawings,making a part of the same, is afull, clear, and exact descriptionthereof.

Figure l is a perspective view of the movable bed of the tile-machinewith my improvement attached. Fig. 2 is a transverse section of thesame, with an arrangement shown for modifying the application of theprinciple shown in Fig. l. l

The invention which is the subject of this patent relates to that classof tile-cutting machines in which a rocking bed is employed to adapt thetransverse plane of the file-blank to the line of the cutters edgeduring the operation of cutting the ranges of teeth; and it consistsinthe application of cqualizing pressure-springs, or their equivalents,to the said rocking bed for the purpose of better adapting anyinequalities in the surface of the file-blank to the edge of the cutter.

In the accompanying drawings, representing this portion of afile-machine, for improvements in which other Letters Patent have beengranted to me bearing even date herewith, D is the movable carriage,which travels upon an appropriate bed, and D the rocking block uponwhich the blank is placed, the necessity for which rocking block arisesfrom the fact that in order to give the proper barb to the teeth theplane in which the chisel travels and the plane in which the blank travels must be inclined with respect to each other, and as the teeth arecut in diagonal lines, if the transverse plane of the iile-blank remainsparallel with the plane of the horizon, the edge of the chisel will cutthe teeth deeper upon one side than upon the other. If the face of thetile-blank contains no inequalities of surface, after the rocking bedhas been once Aproperly adjusted, the successive teeth will be uniformlycut to the same depth 5 but in practice is impossible to grind thesurface of the blanks so evenly as that some inequalities shall notexist, whereby a further capacity of adjustment of the rocking bed tothe chisel becomes necessary and is accomplished by the means hereinshown. To one end of the rocking bed is attached a segment of aworm-gear, l, which engages with the threads of the worm 2, cut upon ashaft which extends transversely through the bed D, the hole in the bedthrough which it passes being of a greater diameter than that of theshaft, so as to admit of an endwise as well as rotary movement of theshaft in either direction. Each end of the shaft terminates with athumbpiece, 3 3. The spaces between the thumbpieces andthe sides of thebed D are occupied by spiral springs 4 4, which are coiled around theshaft and exert a pressure in opposite directions. The tendency of thesesprings is to keep the rocking bed at the angle which will bring theface of the blank parallel with the edge of the cutter-that is to say,after the bed has been set as nearly as possible in its proper positionby turning the worm shaft to the right or to the left. If there shouldbe any unevenness of surface in the blank which would cause the chiselto cut deeper upon one side than upon the other, the blow of the chisel,being at first harder upon one side than upon the other of the blankwill cause the bed to rock, which it is allowed to do by the springs,and at the same time the jarring which the blow of the chisel makes willcause the worm to turn in the direction to relieve itself, and thus readjust itself to this change in the surface of the blank.

My invention is also equally applicable to file-cutting machines whichdo not, as in this instance, have a movable carriage which moves withthe le-blank, but which feed the blank itself over the surface of thebed, provided that such bed is free to adapt the transverse plane of theblank to the cuttersfedge.

Instead ofsprin gs, a weight or weights could be used, as shown by anarrangement exhibited in Fig. 2, and with equally good effect exert alongitudinal strain in opposite directions upon the worm-shaft, andaccomplish the saine useful result.

What I claim, as of my invention, tn l desire to secure by LettersPatent, is-

The method, substantially as described, of regulating the position ofthe rolling bed of a filecutting machine by means of equalizingsprings,or their equivalents, applied and operating substantially as hereinspecified.

l In witness whereof I have hereunto subscribed my name this 20th day ofFebruary, A. H1864.

WM. T. NICHOLSON. Witnesses:

BENJ. F. THUnsToN, BYRON SPRAGUE.

